Luminescence and EPR studies of ultraviolet light emitting La 2 Zr 2 O 7 :Gd 3+ phosphor powder

The Gd3+ doped La2Zr2O7 phosphor has been prepared by solution combustion method and characterized using powder X-ray diffraction, scanning electron microscopy, electron paramagnetic resonance (EPR) and photoluminescence spectroscopy. The EPR spectrum of Gd3+ doped La2Zr2O7 exhibits resonance signals having effective g values at g ≈ 1.84, 1.93, 2.0, 3.00, 3.85 and 6.12. Upon UV light excitation (274 nm), the phosphor exhibits a strong and sharp UV emission at 312.5 nm, which is ascribed to 6P7/2 → 8S7/2 transition of Gd3+ ions. EPR and optical investigations of the sample confirm the presence of Gd3+ in the La2Zr2O7 matrix.